The present invention relates generally to the broad area of pressure probes and, more specifically, to a polymer pressure transducer used to obtain accurate dynamic pressure data in the presence of a changing thermal environment.
The task of obtaining remote pressure determinations without the influence of changing thermal conditions has been alleviated to some degree by prior art techniques. The extent of these prior art techniques is given by the following patents:
U.S. Pat. No. 3,060,748 issued to Schwartz on Oct 30, 1962; PA0 U.S. Pat. No. 3,894,243 issued to Edelman et al on July 2, 1975; PA0 U.S. Pat. No. 3,940,974 issued to Taylor on March 2, 1976; PA0 U.S. Pat. No. 3,970,862 issued to Edelman et al on July 20, 1976; and PA0 U.S. Pat. No. 4,366,714 issued to Adorni on January 4, 1983. PA0 an active PVDF transducer which obtains remote pressure readings which are uncorrected for thermal effects; PA0 a thermocouple having a short rise time allowing an output thermal signal which dynamically responds to changing thermal conditions; and, PA0 a compensation amplifier circuit receiving the uncorrected pressure readings and the dynamic thermal signal and producing an output signal representing accurate pressure data which is corrected for changing thermal conditions.
The Taylor device is a temperature sensor which, like the present invention, is formed from polyvinylidene fluoride (PVDF) having both pyroelectric and piezoelectric properties. The two Edelman et al patents show PVDF polymer film transducer sandwich constructions. Adorni discloses a pressure/temperature probe with separate pressure and temperature transducers connected in series to permit temperature correction. Finally, Schwartz shows an accelerometer with temperature correction features. In view of the foregoing discussion, it is apparent that there currently exists the need for a polymer pressure transducer with thermocouple construction that obtains accurate dynamic pressure data in the presence of a changing thermal environment. The present invention is directed towards satisfying that need.